Composite

Part:BBa_K2787028

Designed by: Weiyi Tang   Group: iGEM18_ShanghaiTech   (2018-10-09)


GFP under pT181 Attenuator target sequence

The part carries a GFP reporter under J23100 whose coding sequence is placed seamlessly after pT181 sense target. The GFP reporter should express naturally with no repressive effects. A promoter J23100 - scar - terminator sequence is also included as a control group to the pT181 Antisense. This part is used to indicate the normal expression amount of GFP protein, so that when compared with the results from BBa_K2787027 shows the repressive efficiency of pT181.


Usage and Biology

ShanghaiTech2018-pT181-1.png

A schematic representation of the pT181 attenuator in action

ShanghaiTech2018-pT181-2.png

A schematic representation of the experimental group plasmid. This has the basic pT181 attenuator Antisense under control of a constitutive promoter, as well as a GFP gene downstream of the pT181 attenuator sense target under the control of a constitutive promoter.

ShanghaiTech2018-pT181-3.png

A schematic representation of the positive control plasmid with the GFP gene downstream of the pT181 attenuator sense target under the control of a constitutive promoter, without a pT181 attenuator Antisense on it.

ShanghaiTech2018-pT181-4.png

400x image of positive control under fluorescence microscope.

ShanghaiTech2018-pT181-5.png

400x image of experimental group under fluorescence microscope

ShanghaiTech2018-pT181-6.png

Characterization of pT181 attenuator in DH5-α E.coli cells. OD600 monitored over time for cell lines incorporating the pT181 attenuator in the absence or presence of the pT181 antisense. The result shows that the pT181 antisense is not harmful to the E.coli, which provides convenience for test for fluorescence as we do not need to normalize the OD600.

ShanghaiTech2018-pT181-7.png

Fluorescence monitored over time for cell lines incorporating the pT181 system with pT181 antisense. It shows that the GFP can be expressed in the pT181-attenuator, and the expression level increases gradually.

ShanghaiTech2018-pT181-8.png

Fluorescence monitored over time for cell lines incorporating the pT181 system without pT181 antisense. It matches the curve of how GFP’s expression increases without being repressed, which establishes foundation for measure the repression effect of pT181-attenuator.

ShanghaiTech2018-pT181-9.png

The combination of the two figures above. We could see the sharp difference in the fluorescence between the two curves. This proves our pT181 could repress the expression of GFP as expected, which means our part C is able to produce repression effect as anticipated. This shows that the controller in our Three-Node Feedback Loop is constructed successfully.

ShanghaiTech2018-pT181-10.png

Characterization of pT181 attenuator in DH5-α E.coli cells. endpoint fluorescence (18 hours) for cell lines in the absence or presence of Pt181. The data shows that our Pt181 attenuator could repress the target gene for 98%.

Shanghaitech2018-pt181compare-time.png

Characterization of dual control pT181 system in DH5α strain with pSB1C3 as a vector. Fluorescence over time for cell growth incorporating dual control pT181 or Kyoto pT181 system. From the figure, we can see the fluorescence of the dual control pT181 is always lower than the Kyoto pT181, which means it shows better repression effect.

Shanghaitech2018-pt181compare.png

Characterization of pT181 attenuator in DH5-α E.coli cells. Endpoint fluorescence (18 hours) for cell lines under the control of dual control or Kyoto Pt181. The data shows that our Pt181 attenuator could repress the target gene for 15% than the Kyoto pT181.

Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    INCOMPATIBLE WITH RFC[12]
    Illegal NheI site found at 7
    Illegal NheI site found at 30
    Illegal NheI site found at 177
    Illegal NheI site found at 200
  • 21
    COMPATIBLE WITH RFC[21]
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    COMPATIBLE WITH RFC[25]
  • 1000
    INCOMPATIBLE WITH RFC[1000]
    Illegal BsaI.rc site found at 1050


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